Engine & Transmission Repair for Cummins, Duramax & Power Stroke Trucks

Tombstone Diesel provides professional engine rebuilding and transmission repair for light-duty diesel trucks across Colorado and surrounding states. From dependable daily drivers to custom-built race setups, our in-house team delivers precision, reliability, and performance you can count on.

In-House Engine Building & Custom Race Engines

We perform full diesel engine rebuilds in-house and source competition-ready race engines from top builders, including Industrial Injection and Freedom Racing Engines. Whether you need OEM-spec reliability or high-horsepower performance, we’ll design, assemble, and calibrate the right build for your needs.

Platforms We Service

Ram Cummins – 5.9L & 6.7L (1994–Present)
Chevy/GMC Duramax – LB7, LLY, LBZ, LMM, LML, L5P
Ford Power Stroke – 7.3L, 6.0L, 6.4L, 6.7L

Popular Engine Services

Short/long block builds, cylinder head work, cam & valvetrain upgrades, head studs & fire-ringing, injector & CP3/CP4 solutions, turbo sizing & compounds, tuning setup, and break-in procedures.

Transmission Services & Upgrades

We install, service, and upgrade transmissions from trusted names such as WP Performance, RevMax, BD Diesel, and more. Whether you’re towing, racing, or daily driving, we build transmissions that match your power level and driving needs.

Common Platforms

Ram/Cummins – 47RE/48RE, 68RFE, Aisin AS69RC
GM/Duramax – Allison 1000/2000, 6L90
Ford/Power Stroke – 4R100, 5R110W, 6R140, 10R140

Popular Transmission Upgrades

Billet torque converters, upgraded clutch packs, valve body & pump modifications, deep pans & coolers, shift calibration, and full replacement transmissions.

Why Choose Tombstone Diesel?

Precision in-house engine rebuilding
Expert transmission repair and driveline upgrades
Specialization in Cummins, Duramax, and Power Stroke platforms
Honest diagnostics and dependable timelines
Service backed by years of proven experience and racing knowledge

Service Areas

Our engine and transmission work is performed in Castle Rock, Colorado, serving:

Colorado: Colorado Springs, Parker, Denver, Broomfield, Fort Collins, Greeley, Sterling, and nearby areas
Regional: Wyoming, New Mexico, Nebraska, and Kansas

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